Piston issue
- Thread starter Dudgy
- Start date
My passenger rear piston looked like that but not near as bad. I put it back together n it runs like a top a year later.
Looks like moisture mixed with soot = acid = aluminum pitting. It may be that the motor likes to stop with the exhaust valve to that cylinder open and lets moisture in or head gasket failure for a while in that cylinder.
That's the hottest cylinder in the motor, same one I cracked.
I also see what looks like a crack on that piston.
I still have 2 pistons just like that in my motor today,deliped coated and no problems ......run it.
i wouldnt run that piston, not in a non stock truck at least. i dont like that "knick" on the bottom of the piston in the top picture. Heat and pressure will tear that thing bigger and bigger.
in my opinion, it looks like someone has done head gaskets already,which head gaskets did it have on it? stamped or riveted? reason being i dont remember the head surface being that rough nor scuff marks in multiple directions, having saying that it looks to me like the injector cup has been leaking, could've been due to a previous repair?? yeah the nick in the piston doesnt look healthy at all but a guy should try to clean up the pits (and the nick) as much as he can so they dont create heat spots and then crack for sure, have the head resurfaced and go with it!
I would say the erosion is from a head gasket leak. If it was a heat issue I would think the worst area would be the lip of the bowl. That area looks pretty good considering the condition of the rest of the piston.